Singing Sounds can be created by two different techniques: trills and tralas. A trill is a rapid alternation between two notes, usually a half step or whole step apart. It is often used to add ornamentation to a melody. A trala is a vocal technique that involves rapidly repeating a single syllable or word. It is often used to create a rhythmic effect in singing. Both of these techniques are used to create interesting and unique sounds in singing.